SMO 2015 open q5
Source: SMO 2015 open
March 31, 2018
number theory
Problem Statement
Let n > 3 be a given integer. Find the largest integer d (in terms of n) such that for
any set S of n integers, there are four distinct (but not necessarily disjoint) nonempty
subsets, the sum of the elements of each of which is divisible by d.